EP3153336B1

EP3153336B1 - System for controlling yaw oscillations of a vehicle with trailer

Info

Publication number: EP3153336B1
Application number: EP16002044.2A
Authority: EP
Inventors: Giorno Rolfo; Elio Arnulfo
Original assignee: Rolfo SpA
Current assignee: Rolfo SpA
Priority date: 2015-10-09
Filing date: 2016-09-21
Publication date: 2020-12-30
Anticipated expiration: 2036-09-21
Also published as: ITUB20154258A1; LT3153336T; EP3153336A1

Description

The present invention refers to a system for controlling yaw oscillations of a vehicle with trailer.
In particular, the present invention refers to a system for counteracting a yaw movement applied to the towing system of a truck in order to improve the motion management of the vehicle towing a trailer with central axle.
It is known how risks and dangers of uncontrolled yaw and snaking of truck trailers are an important problem, above all under disconnected road plane conditions, scarce adherence, high descents and vehicle advancement speed (usually over 50 Km/h), wherein these risks can also make the trailer overturn.
Devices are known to limit the yaw motion amplitude, comprising side telescopic arms with dampening effect assembled on both sides of the towing system of the trailer with respect to the vehicle. Such telescopic arms allow strongly limiting the yaw oscillation amplitude. However, a danger remains in case of big sized trailers or with a big weight or load.
The prior art is given, in particular, by document EP1200276B1 , wherein a device is disclosed for dampening the yaw between a road vehicle and its related trailer, such device being composed of a curvilinear dampening guide on which a friction device operates, for example a pneumatic device assembled onto the towing system. The friction device is composed of friction pads pressed against the curvilinear guide by an actuator, for example a pneumatic actuator. The intensity of the pressing force changes depending on the trailer load and/or the vehicle speed, allowing to automatically adjust the yaw dampening. Such adjustment depends on whether the actuator is automatically controlled by the suspension pressure and/or the vehicle speed.
The arrangement of document EP1200276B1 allows controlling the yaw oscillation of a vehicle by introducing a dissipation force through the friction pads against the curvilinear guide, during the relative movement of the trailer with respect to the vehicle.
However, the arrangement of document EP1200276B1 needs a continuous control of the friction force created in order to counteract the energy introduced by the yaw oscillation and therefore does not help solving the problem of creating a stable system which automatically counteracts the yaw oscillation. The document US 7 261 312 B1 discloses a system according to the preamble of claim 1.
The first detachment friction, commonly greater than the dynamic friction, introduces a system rigidity which negatively affects driving the vehicle.
Since friction surfaces are exposed to external agents, the friction coefficient can greatly change with rain, relative humidity, dirt, oils and greased which can be easily deposited.
Moreover, the force introduced through the friction pads is the single counteract to the yaw oscillation phenomenon. In case of wear of the friction pads pressing onto the curvilinear guide, the counteracting effect to the yaw oscillation can be lost. Therefore, it is necessary to make a maintenance program to continuously ensure the dampening efficiency of the friction pads.
Therefore, object of the present invention is solving the above prior art problems, by providing a system for controlling yaw oscillations of a vehicle with trailer which ensures a force capable of counteracting in time the instability phenomena introduced by the yaw of the dynamic system composed of vehicle and related towed trailer, even without dissipating friction forces, under conditions, per example, in which friction is degraded due to the presence of lubricants or humidity or breakage or wear of the pads.
A further object is providing a system for controlling yaw oscillations of a vehicle with trailer which exploits, as elastic force, the same force generated through a system of pneumatic suspensions already in use for vehicle and/or trailer.
The above and other objects and advantages of the invention, as will appear from the following description, are obtained with a system for controlling yaw oscillations of a vehicle with trailer as claimed in claim 1. Preferred embodiments and non-trivial variations of the present invention are the subject matter of the dependent claims.
It is intended that all enclosed claims are an integral part of the present description.
It will be immediately obvious that numerous variations and modifications (for example related to shape, sizes, arrangements and parts with equivalent functionality) can be made to what is described, without departing from the scope of the invention as appears from the enclosed claims.
The present invention will be better described by some preferred embodiments thereof, provided as a non-limiting example, with reference to the enclosed drawings, in which:

Figure 1 shows a perspective view of a first configuration of a towing system of a vehicle connected to a trailer comprising an embodiment of the system for controlling yaw oscillations of a vehicle with trailer according to the present invention;
Figure 2 shows an enlarged part of the previous Figure; and
Figure 3 shows a perspective view of a second configuration of a towing system of a vehicle connected to a trailer comprising a preferred embodiment of the system for controlling yaw oscillations of a vehicle with trailer according to the present invention;
Figure 4 shows a front view of the first configuration, perfectly aligned, of a towing system of a vehicle connected to a trailer comprising an embodiment of the system for controlling yaw oscillations of a vehicle with trailer according to the present invention; and
Figure 5 shows a perspective view of an enlarged part derived from the previous Figure.

With reference to the Figures, it is noted that a system for controlling yaw oscillations of a vehicle with trailer comprises oscillating means 1 and abutment means 2 interacting with the oscillating means 1 through at least one actuator 3 adapted to counteract the relative movement energy between the vehicle and the trailer.
In particular, the Figures show a preferred embodiment of the system according to the present invention, which will be described below as an example, in which the oscillating means 1 are oscillating, by means of at least one lever 11, with respect to the vehicle and the abutment means 2 are integral with the trailer: in this case the abutment means 2 comprise at least one concave housing 21 adapted to receive, and possibly stably house, the oscillating means 1 so that the longitudinal vertical centerline plane of the vehicle is aligned with at least one longitudinal trace of the longitudinal vertical centerline plane of the trailer.
It is however clearly evident to the skilled person in the art that a system could also be provided in which, conversely, the oscillating means 1 are oscillating, by means of at least one lever 11, with respect to the trailer and the abutment means 2 are integral with the vehicle without thereby departing from the scope of the present invention: the abutment means 2 comprise at least one concave housing 21 adapted to receive, and possibly stably house, the oscillating means 1, by means of at least one lever 11, so that the longitudinal vertical centerline plane of the trailer is aligned with at least one longitudinal trace of the longitudinal vertical centerline plane of the vehicle. It follows, obviously, that what is described herein below with reference to the example embodiment of the Figures, can be easily modified by the skilled person in the art in order to adapt it to this latter and further possible embodiment of the system according to the present invention, even if not specifically shown and described.
The lever 11 comprises at least one roller 12 pivoted with respect to the lever 11 adapted to slide with respect to the concave housing 21 and allow the abutment means 2 to receive, and possibly stably house, the oscillating means 1.
With reference to Figure 3, it is possible to note that the abutment means 2 comprise at least one guide 22, 23 adapted to allow the free sliding of the roller 12.
In particular, per a slanting of the vehicle with respect to the trailer which is greater than a given angle, the roller 12 is uncoupled with respect to the concave housing 21.
According to the invention, the roller 12 lays with its own rotation axis in the longitudinal vertical centerline plane of the vehicle (or of the trailer, in case of the not shown embodiment of the system according to the present invention), while the concave housing 21 and at least one of such guides 22, 23 lay symmetrically with respect to the longitudinal vertical centerline plane of the trailer (or of the vehicle, always in case of the not shown embodiment of the system according to the present invention).
With reference to Figures 4 and 5, it is possible to note that the concave housing 21 is composed of a pair of symmetrical planes slanted by about 45°, the roller 12 being therefore adapted to press against the pair of planes slanted by about 45° remaining lifted with respect to the bottom of the concave housing 21.
Preferably, the actuator 3 comprises at least one elastic element 31 adapted to exert a controlled force onto the abutment means 2, through the oscillating means 1, depending on at least one chosen parameter, per example and preferably, between the transported load, the speed of the vehicle with trailer, a slant angle of the trailer with respect to the vehicle.
Preferably, the elastic element 31 exerts a force having an increasing amount when the movement speed of the vehicle increases, and a force having a minimum or null amount when the slant angle of the trailer with respect to the vehicle increases.
According to a preferred embodiment, the elastic element 31 comprises at least one pneumatic spring. Moreover, the energy used to drive the actuator 3 derives from a suspension system of the vehicle and/or of the trailer like those substantially known in the art.
The system for controlling yaw oscillations of a vehicle with trailer can further comprise dampening devices to degrade the rubbing energy in order to obtain a dampening effect of the yaw oscillations. In particular, the roller 12 can be pivoted with respect to its own rotation axis through at least one sliding support.
The system for controlling yaw oscillations of a vehicle with trailer of the present invention reaches its preset objects.
Substantially, such system is based on a roller integral with the tractor, which presses onto a concave housing integral with the trailer in the rudder. According to the invention the roller is pressed downwards onto the concave housing through a pneumatic spring, but it could be any elastic element which can provide a force and absorb height variations. The concave housing is placed so that the roller is inserted when tractor and trailer are longitudinally aligned. When the trailer tends to move away from this balance by rotating on the towing member along a vertical axis, creating an angle between the two vertical planes passing by the longitudinal axis of tractor and trailer, the vertical force of the roller on one of the two slanted planes, according to the rotation direction, creates a transverse component, which tends to bring back tractor and trailer aligned to the longitudinal vertical plane of the vehicle assembly. This happens as long as the roller does not exceed the angle of the concave housing and the plane on which it rests becomes horizontal. The concave housing is sized so that this point corresponds to such an angle between the longitudinal vertical planes that it is created usually only for road bends which can be travelled only ad limited speeds, lower than 50 km/h. Under these conditions, experience shows that yaw oscillations phenomena are very limited, if not non-existing. When the vehicle travels on bends having a narrow radius, in which the angle between tractor and trailer assumes high values, even near 90°, like in hairpin bends or in maneuvers, the roller goes out of the concave housing. This latter one, in fact, has a short transverse development to allow the vehicle assembly its own described great angle without interfering with the towing members of the tractor. Under these conditions, however, the vertical force is strongly limited by reducing the pressure in the pneumatic spring. In fact, this happens only at very low speeds. The system then operates only at greater speeds, approximately at 40 - 50 km/h.
The intensity of the transverse force depends on the vertical force and on the angle of the slanted plane. The system is almost insensitive to relative rotations between tractor and trailer along the respective horizontal axes, thereby allowing the vehicle assembly to travel on different roads without negatively affecting the guide.
With respect to known devices, differences and following obtained advantages are substantial:

the system according to the present invention is not based on friction, but on exploiting slanted planes;
the system according to the present invention allows completely removing the sliding noise;
the system according to the present invention is efficient only when necessary, for small yaw angles.

Claims

System for controlling yaw oscillations of a truck with trailer, said system comprising oscillating means (1), abutment means (2) interacting with said oscillating means (1) through at least one actuator (3) adapted to counteract a relative movement energy between said vehicle and said trailer by exerting a vertical downward-pressing force between them through a pneumatic spring or any elastic element which can provide a force and absorb height variations, characterized in that said abutment means (2) comprise at least one concave housing (21) adapted to receive said oscillating means (1), said oscillating means (1) being oscillating, by means of at least one lever (11), with respect to said vehicle and said abutment means (2) being integral with said trailer so that a longitudinal vertical centerline plane of said vehicle is aligned with at least one longitudinal trace of a longitudinal vertical centerline plane of said trailer, or said oscillating means (1) being oscillating, by means of at least one lever (11), with respect to said trailer and said abutment means (2) being integral with said vehicle so that a longitudinal vertical centerline plane of said trailer is aligned with at least one longitudinal trace of a longitudinal vertical centerline plane of said vehicle, said lever (11) comprising at least one roller (12) placed at the center of said lever (11) in said concave housing (21) and being actuated by said actuator (3), said roller (12) being pivoted with respect to said lever (11) in order to slide with respect to said concave housing (21) and allow said abutment means (2) to receive said roller (12) of said oscillating means (1) into said concave housing (21), said concave housing (21) being adapted to receive, and possibly stably house, said oscillating means (1) so that the longitudinal vertical centerline plane of the vehicle is aligned with at least one longitudinal trace of the longitudinal vertical centerline plane of said trailer, said roller (12) pressing onto said concave housing (21) integral with the trailer, said roller (12) being pressed downwards onto said concave housing (21) through said pneumatic spring or said elastic element, said concave housing (21) being placed so that said roller (12) is inserted when tractor and trailer are longitudinally aligned, said abutment means (2) comprising at least one guide (22, 23) adapted to allow a free sliding of said roller (12), said roller (12) being uncoupled with respect to said concave housing (21) for a slanting of said vehicle with respect to the trailer which is greater than a given angle, said roller (12) laying with its own rotation axis in a longitudinal vertical centerline plane of said vehicle or of said trailer, and in that said concave housing (21) and said at least one guide (22, 23) lay symmetrically with respect to said longitudinal vertical centerline plane of said trailer or of said vehicle.
System for controlling yaw oscillations of a vehicle with trailer according to the previous claim, characterized in that said concave housing (21) is composed of a pair of symmetrical planes slanted by about 45°, said roller (12) being adapted to press against said pair of planes slanted by about 45° remaining lifted with respect to a bottom of said concave housing (21).
System for controlling yaw oscillations of a vehicle with trailer according to any one of the previous claims, characterized in that said actuator (3) comprises at least one elastic element (31) adapted to exert a controlled force onto said abutment means (2) through said oscillating means (1) depending on at least one parameter, said parameter being preferably chosen among transported load, speed of said vehicle with trailer, slant angle of said trailer with respect to said vehicle.
System for controlling yaw oscillations of a vehicle with trailer according to the previous claim, characterized in that said elastic element (31) exerts a force having an increasing amount when the movement speed of said vehicle increases, and a force having a minimum or null amount when said slant angle of said trailer with respect to said vehicle increases.
System for controlling yaw oscillations of a vehicle with trailer according to the previous claim, characterized in that said elastic element (31) comprises the pneumatic spring and in that an energy used to drive said actuator (3) derives from a suspension system of said vehicle and/or of said trailer.
System for controlling yaw oscillations of a vehicle with trailer according to claim 1, characterized in that it comprises dampening devices to degrade a rubbing energy in order to obtain a dampening effect of said yaw oscillations and in that said roller (12) is pivoted with respect to its own rotation axis through at least one sliding support.